An apparatus for collecting dust from a gas stream by centrifugal forces, as described in German utility model No. 17 03 648, essentially consists of restraining (barrier-forming) and deflecting members arranged in alternation in a gridlike array. Each of the deflecting members consists of two deflecting plates, which are symmetrically arranged with respect to the plane extending in the general direction of gas flow, and a stripping plate. The plates together enclose a cavity which communicates with the space that is traversed by the gas through gaps between the downstream edges of the deflecting members and the upstream edges of the stripping plate.
It has been found that this apparatus results in a relatively high pressure drop and can collect from the gas stream up to 20%, at best, of the quantity of dust that is to be removed. It also effects a classification because the coarser dust fraction preferentially enters the cavity.